Method and system for applying materials on a substrate

ABSTRACT

Embodiments of the invention are directed to a method of printing lines. A method may include positioning a plurality of print units according to a predefined spacing parameter. A method may include depositing material on a substrate by a plurality of print units to form a respective plurality of parallel lines according to a predefined spacing parameter. A printing unit may be positioned at an angle with respect to a predefined scan direction such that a predefined width of a printed line is achieved. A substrate may be rotated between scans such that a plurality of lines in a respective plurality of directions is printed in a scan direction.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of and claims priority from U.S.application Ser. No. 13/131,392, § 371(c) date Aug. 4, 2011, which is aU.S. national application of PCT International Application No.PCT/IL2009/001125, filed Nov. 30, 2009 that claims the benefit of U.S.provisional Application No. 61/118,653, filed Nov. 30, 2009, all ofwhich are incorporated herein by reference.

BACKGROUND OF THE INVENTION

Introducing non-contact deposition technologies, such as inkjet printingor aerosol dispensing in the manufacturing of solar cells, flat paneldisplays, thin film transistors (TFT) or printed circuits may enabledepositing conducting lines on a substrate. The required conductivity ofconducting lines may need to be balanced with various other requirementsor constraints. For example, while wider conducting lines may betterconduct electric energy produced by solar cells, they may also block sunor other light required in the process. However, decreasing the width ofthe conducting lines may result in undesirable reduced electricalconductivity. Furthermore, a production, e.g., of solar cells, mayrequire depositing a number of conducting lines in a respective numberof orientations and/or a respective number of widths. In addition,conducting lines are typically required to be deposited in a specificlocation on a substrate and according to a specific distribution thatmay be a predefined distance between the conducting lines or anotherapplicable relation.

Current systems and methods suitable for mass manufacturing of solarcells utilize conveyor processing to translate a substrate in a linearscan along a single axis typically referred to as the “scan axis” or“scan direction”. Such conveyor processing is typically combined with aplurality of nozzles arranged in a print head essentially orthogonallyto the scan axis or direction, often referred to as the “cross scan”axis. However, in prior art systems and methods, when a deposition ofmaterial is to be according to predefined patterns or parameters,nozzles may need to be specially arranged, installed or controlled. Forexample, printing a number of parallel lines on a substrate may requireremoving, disabling, interleaving or otherwise maintaining some of thenozzles. It is a technological challenge to enable system and method fora simple, quick and cost effective deposition of conducting lines on asubstrate according to a predefined set of parameters such as width,orientation and distribution.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter regarded as the invention is particularly pointed outand distinctly claimed in the concluding portion of the specification.The invention, however, both as to organization and method of operation,together with objects, features and advantages thereof, may best beunderstood by reference to the following detailed description when readwith the accompanied drawings in which:

FIG. 1 shows exemplary metallization patterns according to embodimentsof the invention;

FIG. 2 shows an illustration of an exemplary arrangement of printingunits and a related print pattern according to embodiments of theinvention;

FIG. 3 shows an illustration of an exemplary arrangement of printingunits and a related print pattern accordion to embodiments of theinvention;

FIG. 4 shows an illustration of an exemplary arrangement of printingunits and a related print pattern according to embodiments of theinvention;

FIG. 5 shows an illustration of an exemplary arrangement of printingunits and a positioning unit according to embodiments of the invention;

FIG. 6 shows an illustration of an exemplary arrangement of printingunits and a positioning unit according to embodiments of the invention;

FIG. 7 shows an illustration of an exemplary arrangement of printingunits and a translation unit according to embodiments of the invention;

FIG. 8 shows an illustration of an exemplary arrangement of printingunits, a translation unit and an exemplary rotation of a substrateaccording to embodiments of the invention; and

FIG. 9 shows an exemplary pattern according to embodiments of theinvention; and

FIG. 10 shows an illustration of a finger line formed by a single arrayof nozzles.

It will be appreciated that for simplicity and clarity of illustration,elements shown in the figures have not necessarily been drawn to scale.For example, the dimensions of some of the elements may be exaggeratedrelative to other elements for clarity. Further, where consideredappropriate, reference numerals may be repeated among the figures toindicate corresponding or analogous elements.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

In the following detailed description, numerous specific details are setforth in order to provide a thorough understanding of the invention.However, it will be understood by those of ordinary skill in the artthat the invention may be practiced without these specific details. Inother instances, well-known methods, procedures, components, modules,units and/or circuits have not been described in detail so as not toobscure the invention.

Embodiments of the invention may be applicable to a variety of printingsystems and methods. For the sake of clarity and simplicity exemplaryembodiments and references of non-contact material deposition systemswill mostly be for the application of fabrication of conducting metallines for microelectronics, flat panel displays and solar cells using aninkjet system. However, the scope of the invention is not limited bysuch exemplary embodiments and may be applied to other depositionsystems, such an aerosol jet deposition system or a dispenser and toother applications, such as graphics, press, mass media, packaging,electronics and others using any suitable inks or dispensing materials.

Embodiments of the invention are directed to method of printing lines,for example electrically conductive lines by non-contact depositionmethods. For example, the method may include depositing material, suchas silver on a substrate such as a semiconductor wafer from a pluralityof inkjet nozzles to print electrically conductive contact lines. Theline may be designed to have a desired dimension, e.g., width that wouldsatisfy the conductivity requirements. Embodiments of the invention arealso directed to depositing conducting lines according to predefinedparameters such as orientation, width or location of one or more lineson a substrate and/or a parameter related to spacing values or otherrelation between lines. Such embodiments may be advantageous, forexample, if depositing metallization patterns on a front side ofphotovoltaic cells.

As described herein, according to prior art, printheads or other printunits are positioned along a direction or line that is perpendicular ororthogonal to a scan direction or axis. According to some embodiments, aplurality of printheads or other print units may be positioned along ascan axis or direction. The printheads thus positioned may further beinstalled, spaced or placed according to a desired and/or predefinedspacing parameter or value. For example, three printheads may beinstalled along a scan direction and may further be separated or spacedsuch that three respective lines printed by such three printheads arespaced or are at a predefined distance from each other. Such arrangementmay be combined with conveyor processing as described herein and knownin the art. For example, a number of parallel lines may be printed ordeposited at a number of locations on a substrate by a respective numberof printheads arranged along a scan axis and by translating thesubstrate along the scan axis by a conveyor. As described herein,embodiments of the invention may enable printing of parallel lines atvarious spacing values, parameters or distances and according to otherparameters. According to embodiments of the invention, possibly inaddition to being arranged to produce parallel lines as describedherein, printheads installed or positioned at an angle with respect tothe scan axis or they may be tilted, rotated or otherwise positionedsuch that a width of a printed line is according to a predefinedparameter. For example, in a single scan, a narrow second line may beprinted in parallel to a wider first line at a distance of 2 centimeters(cm), and a third, yet wider line may be printed in parallel to thefirst and second lines in a distance of 1.5 cm from the second line. Asdescribed herein, printheads or other relevant printing units may bearranged to accommodate any applicable pattern.

Although embodiments of the invention may be applicable to a variety ofprint systems, methods and purposes, for the sake of clarity andsimplicity, front side metallization of solar cells will mostly bereferred to herein. However, it will be recognized that embodiments ofthe invention are not limited by or restricted to examples describedherein and accordingly may be applicable to any applicable system,method or purpose.

Front side metallization of solar cells typically comprises equallyspaced, thin conductive lines, often referred to as “fingers” or “fingerlines”. Finger lines are used to conduct the photo generated current toelectrical terminals that enable a solar cell to provide electric power.The spacing between the lines may be a compromise between the demand toreduce losses due to the resistance of the material comprising thephotovoltaic element, and the requirement to minimize shadow losses. Atypical spacing between finger lines is 2 mm, where the line width maydepend on the technology of manufacturing and may be under 100 μm. Forphotovoltaic elements comprising large areas, or when several solarcells are interconnected together to form a solar module, the fingersmay have insufficient conductivity to efficiently conduct the photogenerated current to the electrical terminals. The common approach toovercome this is to use several, e.g., two of three wider linesorthogonal to the finger lines called “bus-bars”, or “tabs” to collectthe photo generated current from the fingers, and to connect to othersolar cells or to terminals. The bus bars are typically 1.5 to 3millimeter (mm) in width.

Reference is now made to FIG. 1 showing exemplary metallization patternsaccording to embodiments of the invention. As shown by FIG. 1, a numberof parallel, thin finger lines 103 may be deposited at a particularspacing, as shown by 104. Another set of parallel lines 101 that may bewider, e.g., the bus lines as described herein, may be printed accordingto a second spacing parameter as shown by 102. Accordingly and as shownby FIG. 1, embodiments of the invention may be configured to deposit aplurality of parallel lines according to at least a respective pluralityof spacing parameters and a respective plurality of width parameters.

The pattern shown in FIG. 1 may be an example of a typical pattern thatmay be useful, e.g., in a mass production of solar cells. For the sakeof clarity, this pattern will be further referred to herein, however, itwill be recognized that this exemplary pattern is referred to herein asan example and that various other patterns, width, spacing or otherparameters may be used in conjunction with embodiments of the invention.As described herein, patterns such as a finger lines 103 and bus linesor bars 101 may be applied by dispensing metallization material from oneor more nozzles that may be installed in a print unit while thesubstrate is scanned beneath, in a scan direction. Therefore, an arrayof jetting nozzles oriented along a scan axis may be suitable forforming conducting lines of photovoltaic solar cells according to thepattern shown in FIG. 1.

According to embodiments of the invention and as described herein, aplurality of lines, e.g., metallization lines may be printed ordeposited by a respective plurality of print units. According toembodiments of the invention each metallization line may be depositedfrom or by a single array of nozzles oriented along the scan axis. Sucharray of nozzles may be fitted on or associated with a single printunit, e.g., a print head as known in the art. A printing unit mayinclude any applicable number of nozzles e.g., hundreds of nozzles. Apattern applied according to embodiments of the invention as describedherein may require a reduced amount of metallization material, and canbe applied, for example, by an inkjet printer having a significantlyreduced number of inkjet elements. In some embodiments, a line may beprinted by an array of deposition elements arranged in a linear arrayoriented essentially along the scan axis of a substrate.

Reference is now made to FIG. 2 that shows illustrations of an exemplaryarrangement of printing units and a related print pattern according toembodiments of the invention. As shown in FIG. 2 a printing system 200may comprise print units 201, 202, 203, 204 and 205 each comprisingdispensing nozzles, such as nozzles 210, 211, 212 and 213 fitted onprint unit 201 and nozzles 215, 216 and 217 installed on print unit 205.As shown, the printing units may be arranged along the scan direction(as shown by coordinate system 270) such that nozzles which are part ofa single printing unit may print a corresponding line on substrate 260.

As shown by arrows 220, print units may be shifted, translated orotherwise positioned or repositioned according to a predefined spacingparameter. For example, in order to produce 5 parallel lines at aspecific distance from one another, print units 201-205 may bepositioned according to such predefined spacing parameter and as shownby FIG. 2. For example, line 230 may be printed by printing unit 201;line 231 may be printed by printing unit 202 and so on. As furtherdescribed herein, other printing arrangements are likewise applicablewithout departing from the scope of the invention. As shown by FIG. 2,in some embodiments, lines such as finger and/or bus lines may bedeposited or printed at a fixed spacing and/or width. However,embodiments of the invention are not limited in this respect.

According to prior art, a print head is typically manufactured with apredetermined spacing of nozzles in order to enable printing of parallellines, e.g., positioning the printhead along a cross scan axis. However,when different patterns are required, e.g., a different spacing betweenparallel lines, the print head may no longer be used and accordingly,may be replaced by another print head. As described herein, according toembodiments of the invention, rather than replacing print heads orunits, they may simply be repositioned in order to accommodate aplurality of patterns.

Reference is now made to FIG. 3 that shows illustrations of an exemplaryarrangement of printing units and a related print pattern according toembodiments of the invention. As shown by FIG. 3, print units or printheads may be moved, shifted or otherwise positioned in order to enableany spacing between printed lines. In some cases, some print heads orunits may be disabled, e.g., in order to achieve large spacing ordistances between printed lines. As shown in FIG. 3, print units 201,202, 203, 204 and 205 may be rearranged in order to achieve a patterndifferent from the pattern shown in FIG. 2. For example, print unit 202may be removed, print unit 203 may be moved left towards print unit 204and print unit 204 may be moved right towards print unit 203.Accordingly, spacing or distances between resulting lines 311, 312, 313and 114 formed on substrate 360 may be different from that of lines230-234 shown in FIG. 2.

As described herein, a distance between printed lines may be determinedand/or achieved by properly positioning print units or print heads, forexample, as shown by FIG. 2 and/or FIG. 3. In some embodiments, adesired width of a printed line may be achieved by tilting, diagonallypositioning, rotating or positioning a print unit at an angle withrespect to a scan direction.

Reference is now made to FIG. 4 that shows illustrations of an exemplaryarrangement of printing units and a related print pattern according toembodiments of the invention. As shown in FIG. 4, print units 410 and411 may be rotated, tilted, turned or otherwise positioned at an anglewith respect to a scan direction as shown by scan direction arrow 440,e.g., as shown by angle 0 450. Accordingly and as shown, a correspondingwidth of printed lines 412 and 413 may result. According to embodimentsof the invention, positioning print units at an angle as shown in FIG. 4may be according to a number of considerations, constraints and/orparameter. For example, a tilt or angle of a print head may be accordingto a desired width of the printed line. Another consideration may be alevel of overlapping of deposited material. For example, when the 0angle between print head 411 and the scan direction is ninety degrees(90°), a full overlap may result, namely, nozzles 420 and 430 shown onprint head 411 may fully overlap, accordingly, nozzle 430 may depositmaterial substantially on the same location material was deposited bynozzle 420. However and as shown, decreasing the angle 0 to any valueunder ninety degrees (90°) may result an overlap of deposition ofmaterial, namely, only some of the material deposited by a first nozzlemay be deposited on top of material deposited by another nozzle fittedon the same print head or unit. Accordingly, embodiments of theinvention may control a level of overlapping by adjusting, configuringor otherwise controlling an orientation of a print unit.

For example, while finger lines described herein are typically narrowlines, bus bars are typically wider. Accordingly, a number of printunits may be positioned at an angle as described herein in order todeposit a respective number of bus lines or a number of print units maybe positioned at an angle as described herein in order to deposit asingle bus or other, possibly wide line. A specific width of a line maybe achieved by a specific tilt of a print unit. For example, id thedistance between nozzles 420 and 430 is D then in order to cause printunit 411 to deposit a line of width W a tilt angle 0 may be chosen suchthat W=D(cos(0)). Any applicable parameter may be taken into accountwhen calculating an angle (e.g., 0) of a print head relative to a scandirection. For example, a length of the print unit, the number ofnozzles fitted on the print unit, the spacing or distance betweennozzles on a print unit, a level of overlapping of deposition and adesired width of a printed line may be considered when tilting a printunit as shown in FIG. 4 and described herein. The number of nozzles,their respective spacing a desired width of a line and a desired levelof overlapping may all be addressed by appropriate calculations. As anexample, for dot size of 50 μm in diameter and a 50% overlapping 40inkjet elements may be required in order to cover a cross scan segmentof 1 mm. Such calculations may be performed in order to determine anangle of rotation or tilt (e.g., 0 in FIG. 4), possibly taking intoaccount various related parameters such as described herein.

Positioning print units or print heads along a scan axis or parallel toa scan axis or direction as described herein may be advantageous in anumber of ways. For example, an orientation of nozzles in arraysparallel to the finger lines has the advantage that deposition ofmaterial may be from multiple nozzles belonging to the same array orprint unit. Therefore, a well known problem in the art known asmis-registration resulting from mechanical misalignment when depositionis performed from nozzles belonging to different print heads may becircumvented or avoided. Correspondingly, the method offers an advantageof significantly simplified calibration procedure of the printeravoiding precise alignment between different print-heads. For example,securing printheads to a position as shown by FIGS. 2, 3 and 4 mayguarantee a precision printing of lines as respectively shown in FIGS.2, 3 and 4.

Embodiments of the invention, for example those described with referenceto FIGS. 2, 3 and 4 may be utilized in various ways. For example, amaterial deposition system may enable high precision printing ordeposition of patterns.

As known in the art, precision or resolution of conveyor based systemsis asymmetric with respect to the scan direction. In the scan direction,the resolution is primarily determined by the scan velocity andresolution or precision, and by the ejection frequency. The resolutionin the cross scan direction is primarily determined by the number of thenozzles per unit length projected on the cross scan direction.Accordingly, the resolution, accuracy or precision in the scan directionare inherently higher than those in the cross scan direction.Embodiments of the invention enable relaxing or reducing constraintssuch as precision or resolution with respect to the cross scan directionby depositing lines of any orientation or direction in the scandirection. According to embodiments of the invention, a substrate may berotated or otherwise positioned such that any line, along any directionor at any orientation is printed while scanning the substrate at thescan direction. Accordingly, in a system according to embodiments of theinvention, high resolution may only be required in one axis and can berelaxed in other, e.g., orthogonal axes. By rotating a substrate, highresolution or precision printing may still be achieved for any patternincluding lines along any direction or at any orientation.

According to embodiments of the invention, a method of applyingmetallization lines by direct-write material deposition printercomprising the steps of forming a first set of metallization linen(e.g., finger lines) by scanning a substrate in an axis parallel to thefirst set of lines, depositing each line from a single column of nozzlesoriented along the scan axis, rotating the substrate, e.g., by 90degrees, and subsequently forming a second set of metallization lines(e.g., bus lines or bus bars) by scanning the substrate in an axisparallel to the second set of lines. It will be recognized that anynumber of such sets of lines may be printed or deposited by such methodand/or as described herein without departing from the scope of theinvention.

The required thickness of metallization lines (e.g., finger lines) foradequate conductivity is achieved by applying metallization ofconsecutives nozzles belonging to the same arrays, preferably in asimile substrate scan. FIG. 10 provides an illustration of finger line31 formed by depositing from a single array of nozzles in a single scan;first layer is applied from nozzle 111, followed by deposition fromnozzle 112 forming the second layer; the third layer is deposited fromnozzle 113, and so forth, the number of layers depends on the desiredline height. Typically adjacent nozzles cannot be used for multi layereddeposition of drops. After the drop lands on the substrate it takes acertain time to dry before subsequent drop can be deposited on top ofthe preceding one. This time interval depends on various details relatedto the chemical composition of the ink, the substrate, and ambientconditions. Depending on the scan velocity of the substrate thisdictates a certain minimum distance between firing nozzles.

Reference is now made to FIG. 5 that shows an illustration of anexemplary arrangement of printing units and a positioning unit accordingto embodiments of the invention. As shown by FIG. 5, a system 500 mayinclude a first plurality of print units 510 that may be arranged asdescribed herein with respect to FIG. 2. System 500 may include a secondplurality of print units 560 that may be arranged as described hereinwith respect to FIG. 4. System 500 may include a positioning unit orassembly comprising a translation table 520 and a rotation unit 530.Rotation unit 530 may be provided with a sensor, such as for example anoptical encoder, which may tracks its motion with a high degree ofprecision and provides feedback to a closed loop operation by thecontrol unit. Rotation unit 530 may be capable of rotation at anyapplicable angle with high precision and resolution. For example,resolutions of better than 2 micro radians (0.4 arc-seconds) withrepeatability of better than 20 micro radians (4 arc-seconds).

As shown, lines 550 may be printed on substrate 540 that may be asilicon wafer or a solar cell. According to embodiments of theinvention, translation table 520 may translate substrate 540 along thescan axis (or X-axis) as shown by coordinate system 570. Accordingly,each of lines 550 may be printed by one respective print unit from printunits 510. Deposition of lines 550 that may be finger lines as describedherein may include positioning print units 510 along or according to thescan direction as shown by coordinate system 570. Print units 510 mayfurther be spaced according to a desired spacing of the finger lines550, e.g., print units 510 may be placed 2 mm apart from one another. Aparticular or specific finger line may be printed by a single printunit. Accordingly, printing a plurality of lines may be achieved by arespective plurality of print units or heads. In some embodiments of theinvention, after material is deposited by print units 510, rotation unit530 may rotate substrate 540, for example, by ninety (90) degrees.

Reference is now made to FIG. 6 that shows an illustration of anexemplary arrangement of printing units and a positioning unit accordingto embodiments of the invention. As described herein, following aprinting of finger lines 550, substrate 540 may be rotated, for example,by ninety degrees (90°). According to embodiments of the invention,following such rotation, substrate 540 may be translated by print units560. As shown by FIG. 6, a set of lines 580, orthogonal to lines 550 maybe printed by print units 560. As shown, the result may be a patternincluding finger lines and bus lines all printed at the scan direction.As shown, lines 580 may be wider than lines 550. Accordingly, printingeach of lines 580 may require more than a single nozzle. As shown, printunits may be installed, fitted, mounted, arranged or positioned in anangle-with respect to the scan direction shown. Accordingly, a number ofnozzles may be used in order to print any one of lines 580 as describedherein, e.g., with reference to FIG. 4. Although exemplary embodimentsdescribed herein include translating a substrate in a scan directionand/or rotating a substrate, other possibilities and/or implementationexist. For example, in some embodiments, rather than or in addition totranslating and or rotating the substrate, print units may be translatedand/or rotated. For example, a first set of print units may betranslated to scan a substrate in a first direction and deposit a firstset of line, e.g., the finger lines and a second set of print units,possibly differently positioned, may be translated to scan a substratein a second direction and deposit a second set offline, e.g., the buslines.

Although exemplary systems and methods described herein include anelement of rotating a substrate, other possibilities are enabled byembodiments of the invention. According to embodiments of the invention,a printing system may include a translation system that enables scanninga substrate in two orthogonal or different axes.

Reference is now made to FIG. 7 that shows an illustration of anexemplary arrangement of printing units and a translation unit accordingto embodiments of the invention. As shown in FIG. 7, a system 700 mayinclude print units arrays 710 and 740 and a translation unit or systemthat may comprise translation stages or units 760 and 770. As shown,substrate 140 may be translated from a first location to a secondlocation by translation stages 760 and 770. Translation or stage units760 and 770 may be combined or otherwise operatively connected such thata substrate 720 may be translated at first and second directions. Forexample and as shown, translation unit 760 may translate substrate 720in the Y direction shown by coordinate system 780 and translation unit770 may translate substrate 720 in the X direction shown by coordinatesystem 780. As described herein, e.g. with reference to FIG. 5, a firstset of lines 730, e.g., finger lines, may be printed or deposited byprint units array 710 while substrate 720 is translated under or inproximity to array 710. Substrate 720 may be carried by translation unit760 to a location where it may be picked up by, or otherwise transferredto translation unit 770. Translation unit 770 may translate substrate720 under or in proximity to array 740 where a second set of lines 750(e.g., bus lines), that may be orthogonal to the first set 720 may bedeposited. It will be recognized that any number of translation unitssuch as units 760 and 770 may be combined in order to translate asubstrate at any suitable, applicable or required direction andaccordingly, lines at any direction may be printed in a scan direction.

Although examples described herein mainly refer to orthogonal scandirections or rotations, other possibilities are enabled by embodimentsof the invention. For example, a rotation of twenty degrees (20°) or ahundred and twenty degrees (120°) is possible. A metallization patterncan be optimized according to various parameters in addition to shadowlosses, such as for example, resistance losses of the semiconductor,charge carrier mean free path, total length of metallization lines, toname a few. Generally therefore the pattern of preference may have anygeometry comprising of metallization lines other than orthogonal linesas described above.

Reference is now made to FIG. 8 that shows an illustration of anexemplary arrangement of printing units, a translation unit and anexemplary rotation of a substrate according to embodiments of theinvention. As shown in FIG. 8, a system 800 may include a plurality ofprint units 510, translation table 520 and a rotation unit 530 asdescribed herein with reference to FIG. 5. Lines 550 may be deposited onsubstrate 540 as described herein with reference to FIG. 5. As shown by810, substrate 540 may be rotated at angle other than 90°. For exampleand as shown, substrate 540 may be rotated at angle of 120°. Referenceis additionally made to FIG. 9 showing a pattern that may be achieved byrotating a substrate by 120° after a first scan and again by 120° aftera second scan. According to embodiments of the invention, after asubstrate has been rotated as shown it may be translated to a second setof print units where a second set of lines may be deposited.Alternatively or additionally, a substrate may be translated back andforth, e.g., in a first direction and then in the reverse direction. Forexample, after substrate 540 has been rotated as shown by 810, substrate540 may be translated back towards print units 510 where a second set oflines may be printed. Accordingly, a substrate may be scanned multipletimes under the same array of print units, print heads or nozzles andmay further be positioned oriented at a different angle relative to thescan axis during each of such multiple scans.

Embodiments of the invention may include an article such as a computeror processor readable medium, or a computer or processor storage medium,such as for example a memory, a disk drive, or a USB flash memory,encoding, including or storing instructions, e.g., computer-executableinstructions, which when executed by a processor or controller, carryout methods disclosed herein.

Unless explicitly stated, the method embodiments described herein arenot constrained to a particular order, or sequence. Additionally, someof the described method embodiments or elements thereof can occur or beperformed at the same point in time or overlapping points in time. Asknown in the art, art execution of an executable code segment such as afunction, task, sub-task or program may be referred to as execution ofthe function, program or other component.

Although embodiments of the invention are not limited in this regard,discussions utilizing terms such as, for example, “processing,”“computing,” “calculating,” “determining,” “establishing”, “analyzing”,“checking”, or the like, may refer to operation(s) and/or process(es) ofa computer, a computing platform, a computing system, or otherelectronic computing device, that manipulate and/or transform datarepresented as physical (e.g., electronic) quantities within thecomputer's registers and/or memories into other data similarlyrepresented as physical quantities within the computer's registersand/or memories or other information storage medium that may storeinstructions to perform operations and/or processes.

Although embodiments of the invention are not limited in this regard,the terms “plurality” and “a plurality” as used herein may include, forexample, “multiple” or “two or more”. The terms “plurality” or “aplurality” may be used throughout the specification to describe two ormore components, devices, elements, units, parameters, or the like.

While certain features of the invention have been illustrated anddescribed herein, many modifications, substitutions, changes, andequivalents may occur to those skilled in the art. It is, therefore, tobe understood that the appended claims are intended to cover all suchmodifications and changes as fall within the true spirit of theinvention.

1. A method of printing, the method comprising: positioning a pluralityof printing units according to a plurality of spacing values andaccording to a predefined scan direction; and while introducing arelative translation between a substrate and said printing unitsaccording to said predefined scan direction, depositing material on saidsubstrate by said plurality of printing units to form a plurality ofparallel lines on said substrate such that said plurality of parallellines are spaced from each other according to said plurality of spacingvalues.
 2. The method of claim 1, wherein said plurality of printingunits comprise a respective plurality of arrays of nozzles arrangedalong a first direction and wherein positioning said plurality ofprinting units is such that said first direction is along said scandirection.
 3. The method of claim 2, wherein each of said arrays formsone of said plurality of parallel lines.
 4. The method of claim 1,wherein within at least one of said line, droplets of said materialpartially overlap.
 5. The method of claim 1, wherein the material iselectrically conductive and the substrate is a semiconductor wafer.
 6. Amethod of printing, the method comprising: positioning at least oneprinting unit at a predefined angle with respect to a scan directionwherein said printing unit comprises an array of nozzles arranged alonga first direction and wherein said angle is determined based on at leastone line width parameter; and while introducing a relative translationbetween a substrate and said printing unit along said scan direction,depositing material on said substrate by said printing unit to form aline on said substrate according to said width.
 7. The method of claim6, wherein within at least one line, droplets of said material partiallyoverlap.
 8. The method of claim 6, wherein the material is electricallyconductive and the substrate is a semiconductor wafer.
 9. A system forprinting, comprising: means for positioning a plurality of printingunits according to a plurality of spacing values and according to apredefined scan direction; and means for introducing a relativetranslation between a substrate and said printing units according tosaid predefined scan direction and for depositing, while introducingsaid relative translation, material on said substrate by said pluralityof printing units to form a plurality of parallel lines on saidsubstrate such that said plurality of parallel lines are spaced fromeach other according to said plurality of spacing values.
 10. The systemof claim 9, wherein said plurality of printing units comprise arespective plurality of arrays of nozzles arranged along a firstdirection and wherein positioning said plurality of printing units issuch that said first direction is along said scan direction.
 11. Thesystem of claim 10, wherein each of said arrays forms one of saidplurality of parallel lines.
 12. The system of claim 9, wherein withinat least one of said line, droplets of said material partially overlap.13. The system of claim 9, wherein the material is electricallyconductive and the substrate is a semiconductor wafer.